Fluorocopolymers have excellent weather resistance, chemical resistance, water and oil repellency, and contamination resistance because of its intermolecular C—F bond with high bonding energy and low polarizability. Owing to such properties, fluorocopolymers have been conventionally used for various purposes. In addition, fluororesin coating materials that are soluble with common organic solvents and cross-linkable at room temperature were developed. For example, Patent Literature 1 discloses copolymers of a fluoroolefin, an alkyl vinyl ether, and a hydroxy alkyl vinyl ether, as coating material resins with weather resistance. Further, Patent Literature 2 discloses copolymers of fluoroolefins, a vinyl ester, an alkyl vinyl ether, and a hydroxy alkyl vinyl ether. Further, Patent Literature 3 discloses copolymers formed of a fluoroolefin, a vinyl ester such as vinyl versatate, a hydroxy alkyl vinyl ether, and an unsaturated carboxylic acid such as crotonic acid.